Apparatus for stripping covered strands



" Ap 1931- J. 5. STULL 1,800,914

APPARATUS FOR STRIPPING COVERED STRANDS Filed April 10, 1926 2 Sheets-Sheet 1 fiwambr John J J/M/ l 14, 1931- .1. s. STULL 1,800,914

' APPARATUS FOR STRIPPING COVERED STRANDS Filed April 10, 1926 2 Sheets-Sheet 2 75 Ail)! Patented Apr. 14, 1931 UNITED sTArEs PATENT; OFFICE j JOHN STANLEY STULL, OF CHICAGO, ILLINOIS, ASSIGNOR TO WESTERN'ELEGTRIC COM- IPANY, INCORPORATED, 015 NEW YORK,

N. Y., A. CORPORATION OF NEW YORK APPARATUS FOR STRIPPING COVERED STRANDS;

Application filed April 10,

This invention relates to apparatus for stripping covered strands, and more particularly to apparatus for stripping insulated electrical conductors.

The object of this invention is to provide an apparatus for stripping the coverings of continuously covered strands for predetermined lengths and at predetermined points throughout their length with speed, accuracy and a minimum of attention.

In accordance with one embodiment of this invention, as applied to an apparatus for skinning the insulation on electrical conductors, there is provided a drum revolving at a uniform speed which carries a plurality of clamping and cutting devices operated at predetermined points in the movement of the drum to successively clamp a pair of twisted conductors drawn from a supply reel to the drum and sever the insulation of the conduc tors at diametrically opposite point-s thereof. A stationary cam member causes a movement of the operative cutting device in a y direction reverse to that in which the drum is moving while the conductors which are clamped to the drum are advanced, thus. moving the insulation back along the conductor cores for a predetermined distance and exposing the bare cores. Thereafter the cutting device is released and disengaged from the conductors which are finally unclamped from the drum and wound upon a take-up reel rotated in synchronism with the drum and simultaneously moved bodily in a longitudinal direction to wind them in even layers upon thereel.

Other objects and advantages of this invention will more fully appear from the accompanying detailed description taken in connection with the accompanying drawings which illustrate one embodiment thereof, in which Fig. 1 is a fragmentary plan view of a conductor stripping apparatus embodying the features of this invention;

Fig. 2 is an enlarged fragmentary sectional view taken upon the line 2-2 of Fig. 1 looking in the direction indicated by the arrows;

Fig. 3 is a detail vertical sectional view 1926. Serial No. 101,042.

taken upon the line 3-3 of Fig. 2 looking in the direction indicated by the arrows;

Fig. 4 is an enlarged detail verticalsectional View taken upon the line 4-4 of Fig. 3 looking in the direction indicated bythe arrows showing the conductors at the completion of the insulation severing operation;

Fig. 5 isa view similar to Fig. 4 only showing the insulation moved back at the completion of the insulation stripping operation and exposing the cores;

Fig. 6 is an enlarged detail horizontal sectional view taken upon the line 6-6 of Fig. 2 looking in the direction indicated by the arrows;

Fig. 7 is a detail horizontal sectional view taken upon the line 7'-7 of Fig. 2 looking in the direction indicated by the arrows, and

Fig. 8 is a view of a pair of twisted insulated conductors as delivered from the apparatus.

As shown in the accompanying drawings, the apparatus is supported upon a base plate 10 having arranged thereon at the left end (Fig. 1) a supply reel 11 carryingin the particular embodiment illustrated, a supply of insulated electrical conductors 12 which are to be bared for a predetermined distance and at predetermined points therealong, the conductors being arranged in pairs having a comparatively long twist (Fig. 8). The supply reel11isrotatablysupporteduponanoverhanging rotatable arbor 13 (dotted outline Fig. 1) in turn carried upon an upright standard 14 provided with a pair of spacedjournals 17 and 18. Fixed to the arbor 13 between one head of the reel 11 and the journal 17 is a collar 19 and surrounding the arbor 13 between the journals 17 and 18 is a compression spring 20, an anti-friction collar 21 being carried free upon the arbor 13 between one end of the spring 20 and the jonrnal 17 with a collar 24 carried upon the arbor 13 and abutting the opposite end of the spring 20. The reel 11 is secured to the arbor 13 by a hand nut 25 screw threaded upon the arbor 13, the nut 25 serving to clamp the reel 11 against the collar 19 which is fixed to the arbor 13. It will be apparent that upon adjustment of the collar of the conductors as-shown in Fig. 7.

24 to suitably compress the spring 20, sufficient friction will be maintained between the collar 19 and the journal 17 to provide a sufficient drag upon the reel to prevent overrunning thereof during operation of the apvparatus.

Intermediate the supply reel 11 and a takeup apparatus 26, to be described in greater detail hereinafter, is a base plate 27 having a pair of spaced upright standards 28 and 29' provided with journals 31 and 32 respectively, rotatably supporting a shaft 33, the shaft being driven in a counter-clockwise directionat a predetermined uniform speed through a suitable source of power (not shown). Rotatably carried upon a pair of stationary studs 34 fixed to the standards 29 upon a horizontal plane above the axis of-the shaft 33' and equally spaced therefrom isa pair of grooved guide rollers 35 (Figs. '1 and 2).

Fixed for rotation with the shaft 33 intermediate the standards '28 and 29 isa drum or cup-shaped wheel 38 (Fig. 7) provided with a continuous peripheral groove 39, which is in line with the grooved rollers 35 (Fig. 1). Carried by the. wheel 38 is a plurality of spring pressed plungers (Fig. 7 which are actuated at predetermined points in the ro-. tation of the wheel 38-to cause the conductors to be gripped within the groove 39 by a stadepression in the wheel 38 within which the sleeve is adapted to reciprocate is a compression spring 46. The plunger 40 is provided with a head 47 having a sliding fit within the .bore of the sleeve 42 and carried within the sleeve between the head 47 and the button 43 is a second compression spring 48 through which the movement'of the sleeve 42 is transmitted to the plunger '40 to cause the gripping the button 43 riding onto the low point of the cam 41 thecompression spring 46 serves to positively free the plunger 40 from the conductors, the spring being compressed during the gripping of the conductors as will readily be apparent. Due to the spring 48 intermediate the button 43'and the head 47 of the plunger 40 it will be apparent that any slight variation in the diameter of the conductors to be stripped will be compensated for by the yieldingof the spring. Formed in the peripheral wall of the cup-shaped wheel 38 at diametrically opposite oints are slots 49 and 50 which extend from t 1 e forward end of the wheel 38 to a vertical inner wall 53 thereof (Figs. 2 and 7).

Mounted upon the shaft 33 within the cupshaped wheel 38 is a pair of nested knife holders 54 and 55 with a shouldered end 56 of each arranged to slide upon one face of the slots 49 and 50. The holders are each provided with elongated openin s 57, the narrow portion of which is su stantially the same width as'thej diameter-of the shaft '33,.

thereby permitting a movement-of the'hold ers toward the periphery of the wheel 38 at predetermined intervals in the rotation of the wheel. The holders 54 and 55 are each normally urged inwardly toward the axis of the wheel 38 by. compression springs 60 housed within openings formed in the inner ends thereof (Figs. 2' and 3),,the springs at one end thereof engaging the periphery ofthe' shaft 33 with the opposite end engaging an adjustable set screw 61.. The shouldered end 56 of each of the knifeholders is normally heldin engagement with'itsassociated heel of the slots 49 and 50', as clearly indicated in dotted outline on 2, by a spring. pressed plunger 62 mounted in a supporting housing 63in turn carried upon the inner vertical wall 53 of the wheel 38'. In the counterclockwise rotation of the wheel 38 theknifeholders54 and 55 are in turn moved outwardly injtheir respective slots 49 and 50 to the positionin-' dicated in dotted outline in 'Fi outward movement. This movement 'iseffected by a stationary cam 64 upon which rides a pa irof rollers 65, .onejca'rriedby each of the holders 54 and 55, the cam64 being" 1 2, which shows the holder 54 at-thejc'ompftion of as;

suitably supported upon the standard 281' It will be apparent from this description the holders are each capable of independent movement toward the periphery of the wheel 38 and are also capable ofind'ependent rotary movement upon the shaft 33 during" the rotation thereof within the limits of the slots 49 and 50 of the" wheel 38, and are pre vented. from movinglongitudinally of the shaft by the inner vertical wall 53 of the wheel at one side and upon the other by the oppositely disposed'vertical face of the'cant' 64 (Figs. 3 and 7 The independent rotary movement of the holders with respect to the shaft 33 will be described.shortlyhereinafter;

A knife '68, which is best shown: in Fi s. '3,

4, 5 and 6, is carried upon the shouldere 'end 56 of each of the knife holders 54 and 55, the knives each being provided with a rojecting portion 69 fitting in a slot forme in its respective holder and secured'in position there" on by a pair of screws 70. The knives and the supporting portions 56 of the holders are slotted at their outer ends as indicated 'at.71 (Fig. 6), the slots being centered with the groove 39 of the wheel 38 so that as the knife holder is moved outwardly, as hereinbefore described, the wires spanning eitherof tlie slots 49 and will be entered within the slot 71, as clearly indicated in Fig. 3. The slot 71 in the portion 56 of the holders is of a width which is substantially the same as the diameter of the insulated wires, thereby serving as a guide for the wire. The extreme outer end of the slot in the knives is provided with a tapered portion 72 for the purpose of guiding the conductors and upon which the cutting edges are formed, the groove 39 of the wheel 38 being similarly tapered. As either of the knives are moved into the slots 49 or 50 of the wheel 38, the conductors are first centered with respect to the balance of the slot 71 in the knife and the slot in the portion 56 of the holder due to the tapered cutting portion 72 of the knife. The balance of the slot 71 of the knife has parallel sides and is of such a width that the conductor core may be entered therein without injury, it being centered therewith due to the guide slot 71 formed in the portion 56 of the holder, as hereinbefore described. The cutting edges 72 of the slot 71 during their movement past the conductors serve to partly sever the insulation thereof, as will readily be apparent, and upon reaching their full outward movement as shown on Figs. 3, 4 and 6, the core will be entered inthe narrow upper portion of the slot 71 with only two very small diametrically opposed portions of the insulation unsevered.

Pivotally supported upon the vertical wall 53 of the rotary wheel 38 at diametrically opposite points is a pair of triangular shaped plates 7 5 and 76, one associated with each of the knife holders. The plates 75 and 76 are carried upon posts 7 7 fixed to the wall 53, as clearly indicated on Fig. 7,. and are positioned outside of the wheel 38 and around the periphery of the cam 64, the sides of the plates adjacent the cam 64 being are shaped. The plates 75 and 76 are normally maintained in the positions shown in Fig. 2 during each rotation of the wheel 38, except as will be shortly described, with a short corner face engaging the periphery of the associated roller 65 and their opposite substantially parallel faces engaging pins 7 8 fixed iii the wall 53 of the wheel 38. As hereinbefore described, the spring plungers 62 serve to maintain the knife holders 54 and 55 in the position shown in Fig. 2 with the shouldered ends 56 against one side of the slots 49 and 50, and the rollers in turn carried uponthe holders 54 and 55 maintain the plates against the pins 78. Secured to the bracket 28 near the base plate 27 is a stationary cam 80, having advancing and receding cam faces 81 and 82 upon which corners 83 of the plates and 76 ride during the rotation of the wheel 38. In the position of the apparatus, as shown in Fig. 2 and as hereinbefore described, the knife 68 has completed its outward movement and has severed the insulation of the conductors at diametrically opposite points (Figs. 4 and 6), and in the continued rotation of the wheel 38 the complete severing and stripping or pushing back of the insulation upon. the conductor cores will be affected. In the position of the parts as just noted, it will be observed that the corner 83 of the plate 75 has just engaged the advancing cam surface 81 of the cam 80, and in the continued rotation of the wheel 38 with the corner 83 riding up the cam surface 81 that the plate 7 5 will be rocked clockwise about its pivot post 7 7 and consequently due to the engagement thereof with the roller 65 the knife holder 54 and its knife 68 will also be rocked clockwise about the shaft 33 against the action of the associated spring pressed plunger 62. This movement. will continue until the corner 83 of the plate 75 rides upon the receding cam surface 82. The extent of the movement of the knife 68in a clockwise direction while the wheel 38 is continuing its counter-clockwise rotation is best shown in Fig. 5, which clearly shows the insulation of the conductors completely severed and stripped or pushed back upon the conductor cores leaving them bare. It will be understood that during the skinning operation the conductors are still gripped to the wheel 38 by the plungers 40 at either side of the slot 49, and that the other knife holder and associated knife 68 will still hold the position shown in the drawings relative to the wheel 38. As the plate 75 rides down the cam surface 82 after the stripping operation, the spring plunger 62 serves to return the associated knife holder and plate 75 to their normal positions, the plate against the associated stop pin 78 and the shouldered portion 56 of the holder against one side of the as sociated slot in the wheel 38. In unison with this latter movement, the roller 65 is riding down the receding surface of the cam 64 and is held in contact therewith by the compression spring 60, so that when the wheel 38 has rotated 180 from the position shown in Fig. 2 the knife 68 carried by the holder 54 will have been drawn inward in the slot 49 to the position in which the knife 68 carried by the holder 55 is shown.

The apparatus 26 for taking up the stripped conductors 12 as delivered from the stripping apparatus will now be described in detail. 'A bracket 83secured to the base plate 10 is provided with a plurality of horizontally disposed journals 84, 85, 86 and 87. Carried by the journals 86 and 87 is a reciprocal and rotatable arbor 88 which has splincd thereto, as indicated at 91, a grooved pulley 92, receiving motion from a similar pulley 93 of larger diameter fixed to the shaft 33 of the stripping apparatus through a belt 94, the belt traveling in the direction indicated by the arrow. Secured to a hub of the pulley 92 and abutting the adjacent vertical face of IOU 38 is caused to rotate.

the journal 86 is a gear 95, the axis of which to a reverse screw threaded shaft 99 rot-atably supported in the journals 84 and 85. The shaft 99 forms part of a distributing or traversing mechanism of a well known type indicated generally by the numeral 100, which it is believed will not need any further description, since this type of mechanism is well known in the art of strand coiling. Fixed to the upper end of the arbor 88, as viewedin Fig. 1, is a collar 101 provided with a circular channel 102 within'which extends an operative'connectmn 103 from the mechanism 100. A take-up reel 104 is secured to theiarbor 88 by a hand nut 105 screw threaded upon the arbor 88, the nut serving to clamp the reel 104 against a collar 106 which is fixed to the arbor 88. As the shaft 33 rotates in a counter-clockwise direction it will be apparent that the arbor 88 will be rotated in a similar direction and through the gears 95 and 96 the reverse screw threaded shaft 99 will be rotated in a clockwise direction to reciprocate the mechanism 100 thereon, the operative connection 103 and collar 101 transmitting such motion to the rotating arbor 88 carrying the reel 104, thuscausing the stripped conductors to be wound upon the reel 104 in even layers.

The operation of the apparatus it is be lieved will be clearly apparent from the foregoing description, but briefly stated is as follows: Assuming that a supply reel 11 of con- I ductors to be stripped and an empty take-up reel 104 have been properly positioned upon the arbors 13 and 88, respectively, andthe conductors properly threaded from the reel 11 and around the wheel 38 and secured-to the reel 104, the shaft 33 carrying the wheel As the wheel 381'0- tates in the direction indicated by the arrow in Fig. 2, the conductors are guided from the left hand roller 35 (Fig. 2) and into the groove 39 of the wheel 38, it being understood that the spring pressed plungers 40 are in a retracted position between the radially extending dotted lines 108 shown uponthe face cam 41 between which points the low point of the cam occurs (Fig. 1). WVhile the knife holder is being rotated from the position shown in Fig. 2 to the position in which the knife holder 54 is sh0wn,'it is moved out wardly, as hereinbefore explained, due to the roller 65 carried thereby riding upon the advancing surface of the cam. This causes the knife 68 carried by the holder 54'to move into severing engagement with the insulation of the conductors within the-slot 49, as clearly indicated in Fig. 4. The'wheel 38 in continuing to rotate brings the corner 83 of the plate 76 onto the advancing cam face 81, and thereby rocks the plate 7 6 clockwise about itspivot and the knife consequently in a direction reversete that in' which the wheel is moving while the conductors which are clamped to the wheel are drawn throu h it, thus moving theinsulation back along t econductors. Upon the corner 83 'of the plate 7 6 riding onto the receding cam surface 82 of the cam 80, the spring pressed plunger associated with the knife holder55 willcause the latter to assume its normal position against one side of the slot 49, and in unison therewith it is moved inwardly through the energy of the spring as the roller rides upon the receding surface of the cam 64. In the further roller 35 (F ig.2) and thence are'taken up upon the reel 104 in the manner hereinbefore described.

During the actuation of the holder 55 and its associated knife 68, as just described, the other holder 54 and its knife 68" which are shown at the completion of the severing operation will be actuated in the manner described .-I1 connection with the holder 55 and its knife- 68 to strip the conductors and return to their normal position relative to the Wheel 38 and thence with the wheel 38 to the beginning of its cycle at a point intermediate the guide rollers 35 at the upper surface of the wheel-38;

Due to the well balanced construction of the apparatus and the constant speed at which it is operated,-th'e twisted conductors to be stripped will be drawnfromthe supply reel at a substantially constant speed with a sub-,

stantially uniform tension. This allows the apparatusto be operated at a high rate of speed, and with the stripping of the insula tion from the conductors along two spaced portionsthereof for every'revolution of'the wheel 38 the output is very great.

While the apparatus is here shown as operating upon a pair of twisted conductors, it

will be obvious that the apparatus is equally well adaptedto stripeither a greater-hum ber of conductorssimilarly twisted or a single conductor.

What is claimed is: v 11. {In an apparatus for strippin'g'a covered strand, continually, moving means for, draw.- i ing a strand from a supply at a substantially constant speed, meanscarried byth e drawing'means for severing the-covering of the strand at predetermined points throughoutthe length thereof and moving the covering 2. In an apparatus for stripping a covered strand, rotary means for drawing a strand from a supply at a substantially constant speed, means carried by the drawing means designed first to move radially thereof to cause a severing of the covering of the strand at predetermined points throughout their length and secondly to move in a direction reverse to the direction of rotation of the drawing means to move the covering back upon the advancing strand for a predetermined distance, and means for causing the said movements of the severing means in timed sequence during the continued rotation of the drawing means.

3. In an apparatus for stripping a covered strand, a rotary drum for drawing a strand from a supply at a substantially constant speed, said drum provided with a peripheral groove within which the strand is clamped for causing it to move with the drum, means for clamping the strand within the groove during a predetermined rotary movement of the drum, means associated with the drum for severing the covering of the strand at predetermined points throughout the length thereof and moving the covering back upon the strand for a predetermined distance, means for operating the severing means during the continued movement of the drum, and means for causing the operation of the clamping means to clamp the strand to the drum and release the strand therefrom and for operating the severing means in timed sequence during the continued rotation of the drawing means.

4. In an apparatus for stripping a covered strand, a slotted knife member for severing the strand covering, means for causing a continuous relative movement between the strand and the member, and means operating at predetermined intervals during said relative movement to cause the edges of the slot in the knife member to engage and thereby sever the strand covering at predetermined points along the strand.

5. In an apparatus for stripping a covered strand, means for severing the strand covering, means for causing the strand and the severing means to advance simultaneously along a predetermined path, and means for causing the severing means to engage and thereby sever the strand covering and for thereafter causing the severing means to move in a reverse direction along the path to move the covering along the strand for a predetermined distance and thereafter resume its forward movement.

6. In a wire skinning machine, a rotatable drum, a series of knives movably mounted on said drum, a cam, means for feeding insulated wire over said drum, and means for rotating said drum to cause said cam to move said knives in a direction opposite to that of the drum for removing the insulation from said wire at predetermined intervals.

7. In an apparatus for stripping a covered strand, means for drawing a strand from a supply, means cooperating with the drawing means for severing the covering of the strand at predetermined points throughout the length thereof and moving the covering back upon the strand in a direction opposite to the drum, a cam, means for feeding insulated wire over said drum, means to rotate said shaft and said drum to cause said cam to move said knives for removing the insulation from said wire at predetermined intervals, and means for preventing said cam from being rotated when said shaft is rotated;

9. In a wire skinning machine, a plurality of skinning knives, means for feeding insu lated wire through said knives one after another, and meansfor moving said knives in a direction opposite to the movement of the Wire along the surface of the wire while the wire is moving to strip a section of insulation therefrom.

10. In a wire skinning machine, a plurality of skinning knives, means for feeding insulated wire through said knives one after another, and means for moving said knives in a direction opposite to the movement of the wire along the surface of the wire while the wire is moving to strip sections of insulation therefrom, said last means consisting of a cam which moves said plurality of knives one after another.

11. In a wire skinning machine, a plurality of movable knives, means for feeding insulated wire through said knives one after another, an operating member, and means for moving said knives in the direction of the movement of the wire to cause said operating member to move said plurality of knives one after the other in a direction opposite the direction of movement of the wire for stripping a section of insulation from said wire.

12. In awire skinning machine, a rotatable drum carrying a plurality of movable skinning knives, a cam for moving said knives, a spool carrying a supply of insulated wire, a second spool for receiving wire, means for rotating said second spool to pull said wire from the supply spool over said drum, and means for rotating said drum to cause the cam to move said knives to strip the insulation from said wire at predetermined intervals. i a a Y 13. In a wire skinning machine, a rotating drum, a plurality of movable skinning knife assemblies on said drum, means for feeding insulated wire over said drum and through said knife assemblies, and a cam for moving said knife assemblies to remove strips of inion sul'ation from said wire at predetermined inbervalswhile said wire, is moving, said knife assemblies including members for moving said assemblies in a direction opposite to-the I direction of the movement of the wire,

14. In a wire skinning machine, a, rotating drum, aplurality of movable skinning knife assemblieson said drum, means for feeding insulated. wire over said drum and through 9 said knife assemblies, and a cam for moving saidassemblies-to remove strips of insulation from. said wire at predetermined intervals while said wire is moving, said 'knife assembliesincluding members for moving said as- 15 semblies in a direction opposite to the movement of the wire, one of said members carryingadj-ustable knife blades v v 15. In a wire skinning machine, a plurality of movable Skinning knives and an operat- 2 ing member, a spool carrying a supply of insulated wire, a second spool for receiving wire, means :for rotating said second spool to pull said wire from the supply spool and through said knives, and means for moving said knives to cause said member to again move said knives to strip sections of insulation fr m. said Wire at predetermined intervals.

I 16. In a wire skinning machine, a plurality of movable skinning knives, an operating member, a spool carrying asupply of insulated wire, a second spool for receiving wire and for pulling said wire from said supply spool and through said skinning knives,

means for leadin said pulled wire through said plurality of knives one at a time, means for rotatingsaid second spool, and means for moving said knives to causesaid member to again move said knives one after another .40. to remove strips of insulation from said wire at predetermined intervals.

17, Ina wire skinning machine, a plurality of movable skinning knives, an operating member, a spool carrying a supply of ill- 4 sulated wire, a second spool for receiving wire, means for rotating said second spool to pull the wire from said supply spooland through said skinning knives, means for leading said pulled wire through said plurality I of skinning knives one at a time, and means for moving said knives to cause said operating member to again move said knivesone' after another in a direction opposite to the directionof the first movement of the knives 56 to strip 'sectionsof insulation from said wire atpredetermined intervals.

witness whereof, I hereunto subscribe my name this 25 day of March A. 1)., 1926.

JOHN STANLEY STULL. 

